While it, like the others, was built on top of earlier buildings, Structure One did not suffer from subsistence and has survived in excellent condition.
The building has a complex history with at least 3 major phases.
Originally it was bigger, with an interior layout shaped like a double cross and measuring at least 15 metres long.
Because it’s remodelling was not necessitated by subsidence or slumping walls there must have been another reason. It may be that its role, or function, within the complex changed, but whatever the reason, the building was shortened by inserting a large curved wall. Both the original entrances were sealed and a new door inserted into the east wall.
Occupying a central position within the complex, Structure One was flanked by other buildings, but had a large, paved, open space directly to the south, with a standing stone aligned to the southern entrance.
The monolith suggests the paved area was a central focal point, around which was clustered the complex of buildings. Given the alignment, the stone must be at least the same age as Structure One but, because the other buildings respect it, the monolith may pre-date their construction.
Phase two of the building – the most recent – has been completely excavated and future work will concentrate on its first, original, phase.
Structure One was a major repository of stone art, with examples cut into its walls.